How to avoid email blocking?

May 22, 2012 9:43 AM

Help! My emails are getting blocked as spam.

We have 2 web sites and email with those domain names are forwarded to our regular email account. A few days ago, those emails stopped. After talking with our ISP and the web site host, I have learned that our email IP Address (the same for both sites) was being blocked as spam and I will have to wait up to 72 hours for it to get unblocked.

I'm wondering if this has happened to others or if I need to look for a new web host. More important, how can I keep this from ever happening again?

posted by jabo to computers & internet (7 answers total)

I think it's important that you audit all the files hosted at your websites to make sure no one's uploaded anything nasty. It's just as likely that your domains were blocked because someone detected lots of spam containing links to things hosted on your sites as it is that you were blocked because your host sent lots of spam. You should also change your passwords immediately.
posted by RonButNotStupid at 9:50 AM on May 22, 2012 [2 favorites]

RBNS - I didn't think of that. I just checked all the files in both sites and there isn't any hidden porn or viagra links.

Our emails have been spoofed by spammers before. We would receive a bunch of 550 (Mail Delivery Failed) emails with our email as the return address. That hasn't happened.
posted by jabo at 11:36 AM on May 22, 2012

There should be a more verbose reason than "blocked as spam" - you really need to find out exactly why it was blocked.

(Also a few more details on who you're hosted with or at least the type of hosting would be helpful. Dedicated? VPS? Shared? etc and how your sites are installed on those machines.)

Step 1, check your SMTP server's IP in this list: http://www.anti-abuse.org/multi-rbl-check/ - if you are indeed being blocked as SPAM then which lists you ended up on may help point you in the direction of finding the cause.

Step 2, check with your ISP and get them to give you the exact logs (or an exact explanation) of what ran afoul of their SPAM filters.

Step 3, check with your web host - I'm assuming this is a shared host? If so, the "spammers" may well just be other users of the system. That's the crappy part of shared hosting.

Step 4, if Step 3 is the case, ask your web host for an alternative outgoing SMTP setup. Depending on your hosting setup and software this could be easy or it could be very difficult.

Spoofing by spammers is very unlikely to cause you to be branded a spammer - nobody in their right mind blocks incoming spam based on the "from" address because of this rampant spoofing - we'd all be on that list eventually!
posted by Fat Elvis at 12:15 PM on May 22, 2012

Where is your server located? I once had a VPS in Asia and had this problem...
posted by yoyo_nyc at 12:25 PM on May 22, 2012

I'm free, great god almighty I'm freeeeeeeee! I checked Fat Elvis' link above and saw that my IP address was not listed, sent a test email and sure enough I'm unblocked.

Fat Elvis - I'm using shared hosting with Geek Storage. Not sure what you mean by how my sites are installed… I use Dreamweaver to ftp them. I plan to follow Steps 2-4 as soon as I unclench. I thought that if someone had hacked our email sign up form, I would've got a lot of 550 returns… but I didn't so it wasn't.
posted by jabo at 1:57 PM on May 22, 2012

Enable SPF on your mail account. It essentially tells the Internet that if the mail didn't come from a specified list of servers, it's not really you and to ignore it. It'll pretty much eliminate joe-jobbing on your domain. If you use Gmail or something like that make sure you add the appropriate mail servers to the approved list.
posted by COD at 4:15 PM on May 22, 2012

You're experiencing the bane of shared hosting - chances are all the mail for that host comes from the same IP, and you could be talking about potentially hundreds of small sites on a single machine. If one person gets hacked (or misbehaves) then you're all "punished" if you end up on an RBL.

Linked from the RBL Checker above is RBLMon - http://www.rblmon.com/ - they allow you to sign up to have up to three IPs monitored for free. You'll be notified if any of them end up on an RBL. I haven't used it, but it sounds like it may be useful in case this happens again.

Your next step up would be to go to a VPS (virtual private server) where you have your own IP address and full control over the server, right down to "root"-level access. This may be overkill depending on your needs/skill, but it does isolate you from this happening like it will in a shared situation. It also opens a lot more possibilities like running your own SMTP server and control over your hosting setup. (That is, of course, also more than enough rope to totally hang yourself with - but it's also an amazing learning process.)
posted by Fat Elvis at 5:14 AM on May 23, 2012